FMASK
The software called Fmask (Function of mask) is used for automated clouds, cloud shadows, snow, and water masking for Landsats 4-8 and Sentinel 2 images (Qiu et al., 2019). More info regarding the software can be found in its original repository https://github.com/GERSL/Fmask .
BDC uses FMask version 4.2 to generate cloud masks for its Landsat-8 and Sentinel-2 Image Collections, while for it Data Cubes the FMASK band is generated by compositing the existent Image Collection FMASK bands. The following table demonstrates each class pixel value:
FMASK |
|
|---|---|
Class |
Pixel value |
Clear Land |
0 |
Clear Water |
1 |
Cloud Shadow |
2 |
Snow |
3 |
Cloud |
4 |
No Data |
255 |
References
Qiu, S., Zhu, Z. He, B. Fmask 4.0: Improved cloud and cloud shadow detection in Landsats 4–8 and Sentinel-2 imagery. Remote Sensing of Environment 231 (2019).